The robot transport device is used, for example, in a step of processing substrates such as semiconductor wafers and liquid crystal display panels and a step of culturing or testing cells. These steps require the environments (e.g., gas concentration, temperature, and humidity) of the transportation space to be adjusted. In this connection, Patent Literature 1 (see FIG. 4) teaches that gas (inert gas) in the transportation space (wafer conveyance chamber 9) is circulated.